An electric conference system using a large-screen display has been proposed, in which a terminal and a host computer (PC) are connected through a serial cable or the like, and presentation is done by controlling the host PC by the terminal. Only one terminal is connected, and no special procedures are necessary for connection between the terminal and the host PC.
In recent years, however, environments which allow to simultaneously connect a plurality of terminals to a host PC by wireless LAN using IEEE802.11b or Bluetooth™ are becoming popular. For this reason, even a portable terminal such as a PDA (Personal Digital Assistants) or cellular phone can easily be connected to a host PC by using radio communication.
Japanese Patent Laid-Open No. 2001-175602 proposes a technique for generating a password and connecting a device to another device after visually confirming the password. However, this technique can cope with only one-to-one connection but not with connection between a plurality of devices.
In the above-described electric conference system, presentation in an environment with a plurality of portable terminals connected is not taken into consideration.